A wide variety of granular or otherwise flowable products, such as pet food, bird seed, cat litter, and the like, are typically packaged in upstanding, flexible package structures, typically including opposing front and rear panels, and optionally including generally inwardly extending side gussets respectively extending between the front and rear panels of the package. Such packages are provided in a bag-like configuration by closing the bottom of the package, with packages sequentially presented to a filling apparatus while in a generally upright orientation, whereby the desired quantity of contents is deposited, typically by gravity, into each package.
After filling, each package is typically positioned on an associated conveyor for movement to an associated sealing apparatus, whereby the upper portion of the bag-like package is sealed to secure the package's contents. Subsequent to filling, it can be desirable to “condition” each package, that is, position each package between a pair of vertically oriented, generally confronting conditioning conveyor belts, which respectively engage the front and rear panels of each package to “square” each package by urging the front and rear panels of each package into generally parallel relationship, in opposition to the flowable contents of each package, which tend to move downwardly under the influence of gravity. Squaring of each package in this fashion promotes package uniformity, and desirably facilitates subsequent stacking, palletizing, and like handling of the packages as they are assembled for subsequent storage and shipment.
Attendant to package conditioning, air within the package can be expelled through the open top thereof, with some air inevitably entering each package as each package is moved from the conditioning apparatus to an associated sealing apparatus. However, as will be appreciated, any air which enters each package can undesirably detract from its “square” conditioned configuration, and can also undesirably increase the internal volume in the package, prior to sealing, thus undesirably increasing the bulk of each package after sealing.
Accordingly, it is desirable to extract air from within each package, subsequent to conditioning, but prior to sealing, to facilitate maintaining each package in the desired squared, conditioned configuration, while at the same time desirably acting to minimize the bulk or size of each package subsequent to sealing.